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Query: UMLS:C0011854 (type 1 diabetes)
 20,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Islet transplantation offers the prospect of good glycemic control without major surgical risks. After our initial report of successful islet transplantation, we now provide further data on 12 type 1 diabetic patients with brittle diabetes or problems with hypoglycemia previous to 1 November 2000. Details of metabolic control, acute complications associated with islet transplantation, and long-term complications related to immunosuppression therapy and diabetes were noted. Insulin secretion, both acute and over 30 min, was determined after intravenous glucose tolerance tests (IVGTTs). The median follow-up was 10.2 months (CI 6.5-17.4), and the longest was 20 months. Glucose control was stable, with pretransplant fasting and meal tolerance-stimulated glucose levels of 12.5+/-1.9 and 20.0+/-2.7 mmol/l, respectively, but decreased significantly, with posttransplant levels of 6.3+/-0.3 and 7.5+/-0.6 mmol/l, respectively (P < 0.006). All patients have sustained insulin production, as evidenced by the most current baseline C-peptide levels 0.66+/-0.06 nmol/l, increasing to 1.29+/-0.25 nmol/l 90 min after the meal-tolerance test. The mean HbA1c level decreased from 8.3+/-0.5% to the current level of 5.8+/-0.1% (P < 0.001). Presently, four patients have normal glucose tolerance, five have impaired glucose tolerance, and three have post-islet transplant diabetes (two of whom need oral hypoglycemic agents and low-dose insulin (<10 U/day). Three patients had a temporary increase in their liver-function tests. One patient had a thrombosis of a peripheral branch of the right portal vein, and two of the early patients had bleeding from the hepatic needle puncture site; but these technical problems were resolved. Two patients had transient vitreous hemorrhages. The two patients with elevated creatinine levels pretransplant had a significant increase in serum creatinine in the long term, although the mean serum creatinine of the group was unchanged. The cholesterol increased in five patients, and lipid-lowering therapy was required for three patients. No patient has developed cytomegalovirus infection or disease, posttransplant lymphoproliferative disorder, malignancies, or serious infection to date. None of the patients have been sensitized to donor antigen. In 11 of the 12 patients, insulin independence was achieved after 9,000 islet equivalents (IEs) per kilogram were transplanted. The acute insulin response and the insulin area under the curve (AUC) after IVGTT were consistently maintained over time. The insulin AUC from the IVGTT correlated to the number of islets transplanted, but more closely correlated when the cold ischemia time was taken into consideration (r = 0.83, P < 0.001). Islet transplantation has successfully corrected labile type 1 diabetes and problems with hypoglycemia, and our results show persistent insulin secretion. After a minimum of 9,000 IEs per kilogram are provided, insulin independence is usually attained. An elevation of creatinine appears to be a contraindication to this immunosuppressive regimen. For the subjects who had labile type 1 diabetes that was difficult to control, the risk-to-benefit ratio is in favor of islet transplantation.
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PMID:Clinical outcomes and insulin secretion after islet transplantation with the Edmonton protocol. 1128 33

Type 1 diabetes is associated with reduced vascular repair, as indicated by impaired wound healing and reduced collateral formation in ischemia. Recently, endothelial progenitor cells (EPCs) have been identified as important regulators of these processes. We therefore explored the concept that EPCs are dysfunctional in diabetes. The number of EPCs obtained from type 1 diabetic patients in culture was 44% lower compared with age- and sex-matched control subjects (P < 0.001). This reduction was inversely related to levels of HbA(1c) (R = -0.68, P = 0.01). In addition, we demonstrated that patient EPCs were also impaired in function using an in vitro angiogenesis assay. Conditioned media from patient EPCs were significantly reduced in their capacity to support endothelial tube formation in comparison to control EPCs. Therefore, despite culturing the EPCs under normoglycemic conditions, functional differences between patient and control EPCs were maintained. Our findings demonstrate that adverse metabolic stress factors in type 1 diabetes are associated with reduced EPC numbers and angiogenicity. We hypothesize that EPC dysfunction contributes to the pathogenesis of vascular complications in type 1 diabetes.
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PMID:Endothelial progenitor cell dysfunction: a novel concept in the pathogenesis of vascular complications of type 1 diabetes. 1469 15

A two-layer cold storage method (TLM) allows sufficient oxygen delivery to pancreata during preservation and resuscitates the viability of ischemically damaged pancreata in the canine pancreas transplant model. In this study, we applied a short-term preservation of the TLM to human pancreata after prolonged cold ischemia prior to islet isolation, and investigated the mechanisms of resuscitation of the ischemically damaged human pancreas by the TLM. Human pancreata were procured from cadaveric donors and preserved by the TLM for 3.2 +/- 0.5 h after 11.1 +/- 0.9 h of cold storage in UW (TLM group), or by cold UW alone for 11.0 +/- 0.3 h (UW group). Islet isolations of all pancreata were performed using the Edmonton protocol. Islet recovery and in vitro functional viability of isolated islets were significantly increased in the TLM group compared with the UW group. According to the criteria of the Edmonton protocol, 10/14 cases (71%) in the TLM group were transplanted to patients with type I diabetes mellitus compared with only 5/21 cases (24%) in the UW group. In the metabolic assessment of human pancreata, levels of energetic parameters (ATP, total adenylates, and energy charge) were significantly increased, and malondialdehyde (MDA) levels were significantly decreased after the TLM preservation. There was no observable change in the incidence or degree of mitochondrial injury after the TLM preservation. Additional short-term storage by the TLM resuscitates the ischemically damaged human pancreas by regenerating the energetic status and prevents further damage by oxidative stress, ultimately leading to improvements of islet recovery and in vitro function. Use of the TLM following prolonged storage in UW provides an excellent adjunctive protocol for treating human pancreata for the rigors of the islet isolation process.
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PMID:Short-term storage of the ischemically damaged human pancreas by the two-layer method prior to islet isolation. 1504 Jun 7

Human islet transplantation seems to be a very promising clinical procedure for patients with type I diabetes mellitus. The aim of our study was to investigate the influence of in situ intravascular flushing with University of Wisconsin (UW) solution and intraductal collagenase injection at the time of pancreas procurement on the isolated islets and exocrine tissue injury. Our experiments indicated that in situ perfusion with the UW solution has a beneficial effect on pancreatic islets and intraductal distention results in an increase in the concentration of pancreatic enzymes released into the cold preservation solution during ischemic conditions. Cold ischemia reduced islet yield, but pancreas perfusion with the UW solution showed better ischemic tolerance of isolated islets during glucose static incubation. We conclude that intravascular pancreas flushing has a crucial effect on recovery and yield of pancreatic islets and protects against exocrine tissue injury.
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PMID:Pancreatic islets isolation using different protocols with in situ flushing and intraductal collagenase injection. 1520 41

Perfluorocarbons (PFC), which store and release high levels of oxygen, have been examined as oxygen carriers. PFC was first used in organ preservation as a component of the two-layer method (TLM). The TLM is comprised of University of Wisconsin solution [UW] and oxygenated PFC for pancreas preservation. Pancreata preserved in the TLM are oxygenated through the PFC and substrates are supplied by the UW. TLM has been shown to prolong the preservation period and repair pancreatic injury caused by warm ischemia. Currently the TLM was used for pancreas preservation prior to clinical whole organ transplant. In this first clinical trial, the morphologic quality of the human pancreas graft after reperfusion was excellent compared with the pancreas stored in UW. In addition, there was no acute rejection episode of pancreata preserved by the TLM. TLM preservation of human pancreata, without initial cold UW storage, prior to islet isolation, resulted in better isolation results and improved the success rate of islet transplantation. Thus preservation of human pancreata by the TLM has become an important process for successful islet transplantation. Nowadays, PFC is routinely used for pancreas preservation prior to islet isolation, which has had a significant impact on curing type 1 diabetes.
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PMID:Clinical application of perfluorocarbons for organ preservation. 1576 67

Recent advances in clinical islet transplantation have allowed patients with type 1 diabetes to become insulin independent, but the procedure is limited since islets from two donors per recipient are typically required. This limitation arises because within a few days of the islets being embolized into the portal circulation, at least half of the transplanted beta-cells have undergone apoptotic cell death triggered by hypoxic and chemokine/cytokine-mediated stress. We hypothesized that the survival of beta-cells in the early post-transplant period would be enhanced if naturally occurring inhibitor of apoptosis proteins (IAPs) were transiently overexpressed in the grafts. In the present study, we used a growth-regulatable beta-cell line (betaTC-Tet) as a model for beta-cells within islets, and examined whether adenovirally delivered XIAP (X-linked IAP-a highly potent IAP) could enhance beta-cell survival. In vitro, XIAP-expressing betaTC-Tet cells were markedly resistant to apoptosis in an ischemia-reperfusion injury model system and following exposure to cytokines. When Ad-XIAP transduced betaTC-Tet cells were transplanted subcutaneously into immunodeficient mice, the grafts were able to reverse diabetes in 3 days, vs. 21 days for Ad-betaGal transduced cells. This approach may allow more efficient use of the limited existing supply of human islets.
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PMID:XIAP overexpression in islet beta-cells enhances engraftment and minimizes hypoxia-reperfusion injury. 1588 33

Diabetic neuropathy is a debilitating disorder that occurs in nearly 50 percent of patients with diabetes. It is a late finding in type 1 diabetes but can be an early finding in type 2 diabetes. The primary types of diabetic neuropathy are sensorimotor and autonomic. Patients may present with only one type of diabetic neuropathy or may develop combinations of neuropathies (e.g., distal symmetric polyneuropathy and autonomic neuropathy). Distal symmetric polyneuropathy is the most common form of diabetic neuropathy. Diabetic neuropathy also can cause motor deficits, silent cardiac ischemia, orthostatic hypotension, vasomotor instability, hyperhidrosis, gastroparesis, bladder dysfunction, and sexual dysfunction. Strict glycemic control and good daily foot care are key to preventing complications of diabetic neuropathy.
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PMID:Evaluation and prevention of diabetic neuropathy. 1595 41

Autoimmune or type 1 diabetes mellitus (T1DM), accounts for 90-95% of all cases of diabetes, while type 2 diabetes mellitus (T2DM), characterized by impaired insulin sensitivity and production, accounts for the other 5-10%. Atherosclerotic process starts during childhood and recognize several mechanisms that are activated in response to NOXIUS STIMULI and participate in a complex state which is accepted to be a chronic inflammatory state. T1DM patients, especially those with a non-optimal metabolic control, have a higher risk of developing all macrovascular complications such as myocardial infarction, stroke and silent ischemia. Macrovascular disease is mainly associated with hyperglycemia, dyslipidemia, obesity, hypertension, hypercoagulable state, cigarette smoking, lack of exercise, endothelial dysfunction, hyperhomocysteinemia and vascular wall abnormalities. In this paper we review the importance of traditional and non-traditional risk factors for macrovascular complications in children with T1DM and discuss their role in the pathogenesis of the excess cardiovascular mortality in these patients.
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PMID:Macroangiopathy in adults and children with diabetes: risk factors (part 2). 1711 Dec 97

Insulin-dependent diabetes mellitus is a disease characterized by a deficiency of insulin secretion by beta islet cells. Integral pancreatic transplantation and islet cell transplantation represent two possibilities of replacing the beta islet cells. The aim of this paper is to analyze the main aspects of selection criteria of the pancreas donor and surgical methods of preservation for integral pancreas or islet cell transplantation. There are described the pancreas procurements realized by the Center of General Surgery and Liver Transplantation team from Fundeni Clinical Institute between December 2005-December 2006 and correlation between the donor's and pancreas features and the quality of islet cell isolation. The selection of pancreas donor and the accomplishment of pancreas procurement represent important factors in the post-transplantation course of the graft. The data from pancreas/islet cell transplantation centers suggest that the factors that influence positively the course of graft are: the donor's age, body mass index, cold ischemia time.
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PMID:[Human pancreas procurement for pancreas and islet transplantation]. 1741 Jul 25

The most successful approach for restoring normal long-term glucose homeostasis in type I diabetes mellitus is whole-organ pancreas transplantation. Graft pancreatitis is observed in up to 20% of patients and may lead to loss of the transplanted organ. Several pathophysiological events have been implicated in this form of pancreatitis. The most important cause of early graft pancreatitis is ischemia/reperfusion (I/R)-related disturbance of microvascular perfusion with subsequent hypoxic tissue damage. Recently, considerable evidence accumulated that, among a variety of other pathophysiological events, the activation of platelets can contribute to I/R injury in the course of acute pancreatitis experimentally and clinically. This review summarizes the events affecting platelet function and, therefore, pancreatic microcirculation leading to acute pancreatitis. Therapeutic approaches and own results are presented.
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PMID:Pathophysiological role of platelets and platelet system in acute pancreatitis. 1858 42


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